RDFa Breadcrumb provide links back to each previous page the user navigated through to get to the current page or - in hierarchical site structures - the parent pages of the current one.

It gives you a new template tag called rdfa_breadcrumb() that you can place anywhere in your template files. It has inbuilt RDFa content markup, so this will help Google to recognize and display the breadcrumbs on search results as well.